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Spike‐independent release of ATP from Xenopus spinal neurons evoked by activation of glutamate receptors
Author(s) -
Brown Paul,
Dale Nicholas
Publication year - 2002
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2001.013193
Subject(s) - xenopus , glutamate receptor , neuroscience , receptor , chemistry , metabotropic glutamate receptor , biology , biochemistry , gene
As the release of ATP from neurons has only been directly studied in a few cases, we have used patch sniffing to examine ATP release from Xenopus spinal neurons. ATP release was detected following intracellular current injection to evoke spikes. However, spiking was not essential as both glutamate and NMDA could evoke release of ATP in the presence of TTX. Neither acetylcholine nor high K + was effective at inducing ATP release in the presence of TTX. Although Cd 2+ blocked glutamate‐evoked release of ATP suggesting a dependence on Ca 2+ entry, neither ω‐conotoxin‐GVIA nor nifedipine prevented ATP release. N‐type and L‐type channels are thus not essential for glutamate‐evoked ATP release. That glutamate receptors can elicit release in the absence of spiking suggests a close physical relationship between these receptors, the Ca 2+ channels and release sites. As the dependence of ATP release on the influx of Ca 2+ through Ca 2+ channel subtypes differs from that of synaptic transmitter release, ATP may be released from sites that are distinct from those of the principal transmitter. In addition to its role as a fast transmitter, ATP may thus be released as a consequence of the activation of excitatory glutamatergic synapses and act to signal information about activity patterns in the nervous system.